The real property tax is the most important local tax in counties, school districts, and many municipalities. Accurate estimates of the value of real property is vital for the tax to be fair and accurate. These assessments are done by the county assessment office, and are used by all local governments and school districts when levying real property taxes. Assessors determine values for all properties in the county, update records, prepare reports, and in those counties with automated record keeping, may also prepare the tax duplicates. In addition, they prepare change notices that are sent to affected property owners and handle questions of tax exemption for properties owned and used for pure public charity.